1. Technical Field
The present invention relates to a method and system for Bluetooth communication between a Bluetooth device and a plurality of terminals for supporting a Bluetooth function.
2. Related Art
Bluetooth technology replaces multiple cable connections which are required between devices with a single wireless connection within a local area. For example, when Bluetooth wireless technology is implemented in a mobile phone and a laptop computer, the mobile phone and the laptop computer may be used while connected without a cable. Actually all types of digital devices including printers, personal digital assistants (PDAs), desktop computers, fax machines, keyboards, and joysticks may be a part of a Bluetooth system. The Bluetooth wireless technology allows devices to be free from cables, and acts as a universal bridge for forming an interface between an existing data network and peripheral devices, and a particular group between devices spaced apart from a fixed network lower structure. Bluetooth has been designed to be operated even in a radio frequency environment with much noise, and therefore Bluetooth ensures connection using rapid recognition and a frequency hopping method. A Bluetooth module performs new frequency hopping after receiving or sending a packet, thereby avoiding interference with other signals. Compared to other systems which are operated in the same frequency, Bluetooth uses particularly fast and short packets. Hereinafter, a communication method using Bluetooth will be briefly described.
A Bluetooth device that enables intercommunication by a Bluetooth communication method configures a connection state in which communication is performed by performing an operation such as inquiry, inquiry scan, page, page scan, or the like. In this process, a master device and a slave device are determined depending on their roles.
When configuring a new connection state between the Bluetooth devices, an operation clock and a frequency pattern between the Bluetooth devices should be aligned. Inquiry among processes performed to configure the connection state in this manner refers to a process in which a master device repeatedly sends an operating frequency so that a slave device aligns a frequency pattern with that of the master device. Inquiry scan refers to a process which is performed in the slave device, in which a received frequency is detected and synchronization is aligned with the detected frequency. Page refers to a process in which the master device sends a clock signal so that the slave devices are aligned with an operating clock of the master device, and page scan refers to a process in which the slave device detects a received clock and aligns synchronization. A network that is formed in such a manner that at least one slave devices configures a connection state with respect to the master device through these processes is referred to as a piconet.
According to the Bluetooth communication method currently proposed, a single master device in a piconet connects seven slave devices in an active state so that the seven slave devices may perform intercommunication. In addition, in order to connect a new slave device to the piconet, the master device releases the connection in the active state with respect to any one slave device among the seven slave devices which are connected in the active state, and performs communication connection of the active state with the new slave device.
Meanwhile, in the Bluetooth communication method, the master device and the slave device are operated in an active mode for performing normal communication with the slave device and in hold/sniff/park/modes for saving power of a communication device. The hold mode is a typical mode used when there is no need to send data for a relatively long time. The sniff mode is a mode for transmitting and receiving data for a predetermined period of time starting from a specific time that is set between the master device and the slave device. The park mode is a mode for intermittently performing communication between the master device and the slave device so that the slave devices requests to maintain synchronization with the master device and requests switch to the active mode.
The slave device that is operated in any one among the active mode and the hold/sniff/park modes repeatedly performs an operation of a corresponding mode with a predetermined period. Meanwhile, an operation of the slave device operated in the hold mode may be regarded as a periodic operation such as in other modes because the slave device with a fixed time should wake up so as to perform communication with the master device even though the hold mode is a one-time operation mode without a repetitive period.
In this instance, when the slave device connected to the master device is converted into a corresponding mode, the master device sets a communication allocation time with each slave device in the corresponding mode through communication negotiation with the slave device whose mode is to be converted. These slave devices are set so as to be operated with periodicity with respect to the corresponding mode through negotiation with the master device. Accordingly, in the related art, the master device and the slave device may fixedly perform communication with communication allocation time and period set by mutual negotiation before a mode of the slave device is changed.
Meanwhile, for the Bluetooth communication, a pairing process between the Bluetooth devices must be performed first. However, the fact that the pairing process is newly performed every time between new Bluetooth devices may be very inconvenient for users.
Therefore, there is a need to introduce a Bluetooth communication system capable of omitting the pairing process.